study after study that people are driven to eat by factors other than hunger: the eating behavior of their dining companions, the size of the serving spoon, plate or bowl they use, and the amount left in the bowl.
These studies have used both highly palatable foods such as ice cream, as well as foods that are rarely craved, like soup. The results of these studies support Kessler's contention that Americans are driven to eat for reasons other than hunger, but they suggest that causes of overeating are more complex than his book leads us to believe.
Although The End of Overeating briefly mentions Barbara Rolls' research on eating behavior, it deserves more attention. The emphasis in The End of Overeating is on the changes in the types of foods that are now widely available--the hyper-processed and palatable foods. What isn't emphasized enough is the change in portion size. Dr. Rolls and her colleagues have shown that among both adults and children increases in portion size lead to eating more calories. Portion sizes have increased dramatically in the past several decades, and even recipes have changed their serving amounts.
This change may be equally important as the proliferation of highly palatable foods that can causes changed in brain circuitry and result in cravings. Or it may be these changes in combination that we should focus on, since processed highly palatable foods are usually served in large portion sizes.
The last omission worth mentioning is the effectiveness of food industry advertising. A tremendous amount of money is spent on advertising foods, such as breakfast cereals, sugar-sweetened beverages, fast food, and other processed foods high in sugar and fat. Although most people deny that advertisements influence them, studies show that they are indeed heavily influenced. Tom Robinson and colleagues found that young children perceived foods in McDonald's packaging as tasting better than the same food in unbranded packaging.
Taken together, it seems that overeating is caused by a variety of influences in our modern society: the widespread availability of highly processed highly palatable foods high in sugar, fat, and salt; the barrage of advertisements for these nutritionally questionable foods and the restaurants that sell them; the size of the portions we are served; the size of the plates and bowls we use; and the social setting in which we eat. Dr. Kessler is correct in suggesting that many people are being driven to overeat in our modern food environment. But like most tough public health problems, the reasons are even more complex than those offered in his interesting book.